J Vet Diagn Invest
September 2024
Bacillary hemoglobinuria (BH) is an infectious disease, mostly affecting cattle, caused by ( type D), with acute hepatic necrosis and intravascular hemolysis. Cattle are typically predisposed to BH by liver injury caused by , although cases have been reported in cattle without evidence of this parasite. Here we describe a cluster of 14 BH cases from 7 counties in north-central to central Missouri submitted to a veterinary diagnostic laboratory between December 2020 and April 2023.
View Article and Find Full Text PDFToxoplasmosis is a disease of primary concern for Hawaiian monk seals (Neomonachus schauinslandi), due to its apparently acute lethality and especially heavy impacts on breeding female seals. The disease-causing parasite, Toxoplasma gondii, depends on cats to complete its life cycle; thus, in order to understand how this pathogen infects marine mammals, it is essential to understand aspects of the terrestrial ecosystem and land-to-sea transport. In this study, we constructed a three-tiered model to assess risk of Hawaiian monk seal exposure to T.
View Article and Find Full Text PDFA 9-year-old dog was presented with weight loss, respiratory effort, and an enlarged abdomen. Imaging studies and exploratory surgery showed pulmonary and splenic masses and bi-cavitary effusion, later classified as hemorrhage. Cytology of the peritoneal and pleural fluids also revealed several microfilariae.
View Article and Find Full Text PDFToxoplasma gondii is a zoonotic parasite that can cause severe morbidity and mortality in warm-blooded animals, including marine mammals such as sea otters. Free-ranging cats can shed environmentally resistant T. gondii oocysts in their feces, which are transported through rain-driven runoff from land to sea.
View Article and Find Full Text PDFPathogenic bacteria, viruses, fungi, and protozoa can cause food and waterborne diseases. Surveillance methods must therefore screen for these pathogens at various stages of water distribution and of food from production to consumption. Detection using nucleic acid amplification methods offer rapid identification, but such methods have limited utility for characterizing populations, variant types or virulence traits of pathogens.
View Article and Find Full Text PDFThe presence of foodborne protozoan pathogens including Cryptosporidium parvum, Giardia duodenalis, Toxoplasma gondii, and Cyclospora cayetanensis in commercial shellfish has been reported across diverse geographical regions. In the present study, a novel multiplex nested polymerase chain reaction (PCR) assay was validated to simultaneously detect and discriminate these four targeted parasites in oyster tissues including whole tissue homogenate, digestive gland, gills, and hemolymph, as well as seawater where shellfish grow. To differentiate viable and non-viable protozoan (oo)cysts, we further evaluated reverse transcription quantitative PCR (RT-qPCR) assays through systematic laboratory spiking experiments by spiking not only dilutions of viable parasites but also mixtures of viable and non-viable parasites in the oyster tissues and seawater.
View Article and Find Full Text PDFToxoplasma gondii is a ubiquitous zoonotic parasite that can infect warm-blooded vertebrates, including humans. Felids, the definitive hosts, drive T. gondii infections by shedding the environmentally resistant stage of the parasite (oocysts) in their feces.
View Article and Find Full Text PDFWastewater-based epidemiology (WBE) has been deployed broadly as an early warning tool for emerging COVID-19 outbreaks. WBE can inform targeted interventions and identify communities with high transmission, enabling quick and effective responses. As the wastewater (WW) becomes an increasingly important indicator for COVID-19 transmission, more robust methods and metrics are needed to guide public health decision-making.
View Article and Find Full Text PDFEnvironmental monitoring of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for research and public health purposes has grown exponentially throughout the coronavirus disease 2019 (COVID-19) pandemic. Monitoring wastewater for SARS-CoV-2 provides early warning signals of virus spread and information on trends in infections at a community scale. Indoor environmental monitoring (e.
View Article and Find Full Text PDFTesting surfaces in school classrooms for the presence of SARS-CoV-2, the virus that causes COVID-19, can provide public-health information that complements clinical testing. We monitored the presence of SARS-CoV-2 RNA in five schools (96 classrooms) in Davis, California (USA) by collecting weekly surface-swab samples from classroom floors and/or portable high-efficiency particulate air (HEPA) units (n = 2,341 swabs). Twenty-two surfaces tested positive, with qPCR cycle threshold (Ct) values ranging from 36.
View Article and Find Full Text PDFSarcocystis spp. are protozoan parasites that cause a spectrum of lesions in various hosts. Hepatic sarcocystosis and encephalitis have been described in captive American black bears (Ursus americanus) and polar bears (Ursus maritimus), and in a free-ranging grizzly bear (Ursus arctos horribilis), but have not previously been reported in free-ranging American black bears.
View Article and Find Full Text PDFFood and waterborne protozoan pathogens including Cryptosporidium parvum, Giardia enterica and Toxoplasma gondii are a global concern for human public health. While all three pathogens have been detected in commercial shellfish, there is currently no standard approach for detecting protozoan parasites in shellfish. Common molecular and microscopic methods are limited in the number of pathogens they can simultaneously detect and are often targeted at one or two of these pathogens.
View Article and Find Full Text PDFIncreasing reports of marine mammal deaths have been attributed to the parasite Sarcocystis neurona. Infected opossums, the only known definitive hosts, shed S. neurona sporocysts in their feces.
View Article and Find Full Text PDFTransbound Emerg Dis
September 2022
Oocyst shedding in domestic and wild felids is a critical yet understudied topic in Toxoplasma gondii ecology and epidemiology that shapes human and animal disease burden. We synthesized published literature dating from the discovery of felids as the definitive hosts of T. gondii in the 1960s through March 2021 to examine shedding prevalence, oocyst genotypes, and risk factors for shedding.
View Article and Find Full Text PDFProtozoan contamination in produce is of growing importance due to their capacity to cause illnesses in consumers of fresh leafy greens. Viability assays are essential to accurately estimate health risk caused by viable parasites that contaminate food. We evaluated the efficacy of reverse transcription quantitative PCR (RT-qPCR), propidium monoazide coupled with (q)PCR, and viability staining using propidium iodide through systematic laboratory spiking experiments for selective detection of viable Cryptosporidium parvum, Giardia enterica, and Toxoplasma gondii.
View Article and Find Full Text PDFThe prevalence of Toxoplasma gondii exposure in Inuit living in Nunavut (20%) is twice that of the US (11%); however, routes of exposure for Inuit communities in North America are unclear. Exposure to T. gondii in humans has been linked with consumption of raw or undercooked shellfish that can accumulate environmentally resistant oocysts.
View Article and Find Full Text PDFFood Waterborne Parasitol
December 2020
Food and waterborne protozoan pathogens can cause serious disease in people. Three common species , and can contaminate diverse shellfish species, including commercial oysters. Current methods of protozoan detection in shellfish are not standardized, and few are able to simultaneously identify multiple species.
View Article and Find Full Text PDFFood Waterborne Parasitol
June 2019
High prevalences of Cryptosporidium and Giardia were recently found in enteric illness patients in the Qikiqtaaluk region of Nunavut, Canada, with a foodborne, waterborne or animal source of parasites suspected. Clams (Mya truncata) are a commonly consumed, culturally important and nutritious country food in Iqaluit; however, shellfish may concentrate protozoan pathogens from contaminated waters. The goal of this work was to investigate clams as a potential source of Cryptosporidium and Giardia infections in residents in Iqaluit, Nunavut.
View Article and Find Full Text PDFBackground: Toxoplasma gondii is a zoonotic parasite that can have severe implications for human health. Acutely infected cats shed environmentally resistant T. gondii oocysts in their faeces that contaminate soil, and soil can serve as a reservoir of infection for humans.
View Article and Find Full Text PDFWhy some Toxoplasma gondii-infected southern sea otters (Enhydra lutris nereis) develop fatal toxoplasmosis while others have incidental or mild chronic infections has long puzzled the scientific community. We assessed robust datasets on T. gondii molecular characterization in relation to detailed necropsy and histopathology results to evaluate whether parasite genotype influences pathological outcomes in sea otters that stranded along the central California coast.
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